SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37c41f3f09976922c76cc0a744c25223deb44913e5e26be37145a11f5a50f71f' 
  AND token = 'KXOJxsur+lOJkZc+9XGfm2wAnR/wItZU9EtWRtSxvMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}